Vehicle air conditioning and heating system providing engine on and off operation

Abstract

A heating, ventilating and air conditioning (HVAC) system for use in an over-the-road or off road vehicle is provided. The HVAC system may be operated regardless of the operational state of the engine. That is, the HVAC system may be operated to condition the interior compartments of an over-the-road vehicle while the engine is running and while the engine is in a no-idle (off) condition. In general, the HVAC system efficiently shares one or more typical air conditionings components with those already found in the vehicle. In one instance, the HVAC system operates an electrically-driven compressor when a belt-driven compressor is idle. In another case, the HVAC system operates both an electrically-driven compressor and a no-idle condenser when a belt-driven compressor and condenser are idle. In yet another embodiment, the HVAC system shares an evaporator.

What is claimed is: 
     
         1 . An air conditioning system for use in a vehicle having an engine, comprising:
 a primary air conditioning loop including a belt-driven compressor, the belt-driven compressor operable when the engine of the vehicle is operating; and   an electrically-driven compressor thermally coupled to the primary air conditioning loop, the electrically-driven compressor operable when the engine of the vehicle is not operating;   wherein the air conditioning system further comprises at least one valve, the valve routing refrigerant to the belt-driven compressor when the engine of the vehicle is operating and to the electrically-driven compressor when the engine of the vehicle is not operating.   
     
     
         2 . The air conditioning system of  claim 1 , further comprising a no-idle condenser thermally coupled to the electrically-driven compressor and the primary air conditioning loop, the no-idle condenser operable when the engine of the vehicle is not operating. 
     
     
         3 . The air conditioning system of  claim 1 , wherein the at least one valve is operably coupled to a controller to route the refrigerant to the belt-driven compressor when the engine of the vehicle is operating and to the electrically-driven compressor when the engine of the vehicle is not operating. 
     
     
         4 . The air conditioning system of  claim 1 , wherein the primary air conditioning loop includes an evaporator and an accumulator, the accumulator located between the at least one valve and the evaporator. 
     
     
         5 . The air conditioning system of  claim 1 , wherein the primary air conditioning loop includes an evaporator and wherein the at least one valve is coupled between an outlet of the evaporator and at least one of an inlet of the belt-driven compressor and in inlet of the electrically-driven compressor. 
     
     
         6 . The air conditioning system of  claim 1 , wherein the at least one valve comprises a first valve and a second valve, the first valve routing refrigerant to the belt-driven compressor when the engine of the vehicle is operating and the second valve routing refrigerant to the electrically-driven compressor when the engine of the vehicle is not operating. 
     
     
         7 . The air conditioning system of  claim 6 , wherein the second valve is operably coupled to a controller to route the refrigerant to the electrically-driven compressor when the engine of the vehicle is not operating. 
     
     
         8 . The air conditioning system of  claim 6 , wherein the primary air conditioning loop includes an evaporator; the second valve located between an outlet of the evaporator and an inlet of the electrically-driven compressor. 
     
     
         9 . The air conditioning system of  claim 1 , wherein the electrically-driven compressor is a variable speed compressor; the variable speed compressor operably coupled to a controller, the controller controlling the speed of the variable speed compressor. 
     
     
         10 . An air conditioning system for use in a vehicle having an engine, comprising:
 a primary air conditioning loop including a belt-driven compressor, the belt-driven compressor operable when the engine of the vehicle is operating; and   an electrically-driven compressor thermally coupled to the primary air conditioning loop, the electrically-driven compressor operable when the engine of the vehicle is not operating;   wherein the electrically-driven compressor is operably coupled to a controller, the controller controlling the speed of the electrically-driven compressor.   
     
     
         11 . The air conditioning system of  claim 10 , wherein the primary air conditioning loop includes a cab evaporator in thermal communication with a cab interior of the vehicle and a sleeper evaporator in thermal communication with a sleeper interior of the vehicle. 
     
     
         12 . The air conditioning system of  claim 10 , wherein the belt-driven compressor is disabled when the electrically-driven compressor is operating and the electrically-driven compressor is disabled when the belt-driven compressor is operating. 
     
     
         13 . The air conditioning system of  claim 10 , wherein the belt-driven compressor and the electrically-driven compressor are thermally coupled to each other in parallel. 
     
     
         14 . The air conditioning system of  claim 10 , wherein the primary air conditioning loop includes a condenser, and wherein the air conditioning system further comprises an electrically-driven air mover for moving air over the condenser when the engine is not operating. 
     
     
         15 . The air conditioning system of  claim 10 , wherein the electrically-driven compressor is a variable speed compressor. 
     
     
         16 . An air conditioning system for use in a vehicle having an engine, comprising:
 a primary air conditioning loop including a belt-driven compressor, the belt-driven compressor operable when the engine of the vehicle is operating; and   an electrically-driven compressor thermally coupled to the primary air conditioning loop, the electrically-driven compressor operable when the engine of the vehicle is not operating; further comprising a no-idle condenser thermally coupled to the electrically-driven compressor and the primary air conditioning loop, the no-idle condenser operable when the engine of the vehicle is not operating;   wherein a condenser from the primary air conditioning loop is disabled when the no-idle condenser is operating and the no-idle condenser is disabled when the condenser from the primary air conditioning loop is operating.   
     
     
         17 . The air conditioning system of  claim 16 , wherein the electrically-driven compressor and the no-idle condenser are thermally coupled in series with each other and in parallel with a combination of the belt-driven compressor and the condenser which are also thermally coupled in series with each other. 
     
     
         18 . The air conditioning system of  claim 16 , wherein an electrically-driven air mover is disposed proximate the no-idle condenser for moving air over the no-idle condenser when the engine of the vehicle is not operating. 
     
     
         19 . The air conditioning system of  claim 16 , wherein the no-idle condenser and the electrically-driven compressor are operably coupled to a controller, the controller controlling the output of the electrically-driven compressor. 
     
     
         20 . The air conditioning system of  claim 16 , wherein the primary air conditioning loop is divided into a high pressure coolant loop and a low pressure coolant loop by a heat exchanger, the low pressure coolant loop including an evaporator in thermal communication with an interior portion of the vehicle, a coolant pump, and a coolant heater.